A Detroit S60 engine shows a coolant weep hole leak. Which explanation aligns with the source material?

A Detroit S60 engine shows a coolant weep hole leak. Which explanation aligns with the source material?

• A. Leaking liner O-ring is the cause
• B. Cavitation of the cylinder block is the cause
• C. Worn water pump
• D. Loose thermostat housing

Answer: (A)

A coolant weep hole is a diagnostic vent used in engines with cylinder liners sealed by O-rings. In the Detroit S60, the liner O-rings keep coolant out of the combustion chamber and away from the oil paths. If those O-rings fail, coolant can seep past the seal and push through the weep hole to the outside. That seepage through the weep hole is a clear cue that the liner O-ring is leaking, making it the best explanation for a weep hole leak. Other issues tend to show up differently: a worn water pump typically leaks near the pump housing or shaft area; a loose thermostat housing leaks at the housing gasket; cavitation causes erosion-related damage inside cooling passages rather than a focused leak through the liner’s weep hole.

A coolant weep hole is a diagnostic vent used in engines with cylinder liners sealed by O-rings. In the Detroit S60, the liner O-rings keep coolant out of the combustion chamber and away from the oil paths. If those O-rings fail, coolant can seep past the seal and push through the weep hole to the outside. That seepage through the weep hole is a clear cue that the liner O-ring is leaking, making it the best explanation for a weep hole leak.

Other issues tend to show up differently: a worn water pump typically leaks near the pump housing or shaft area; a loose thermostat housing leaks at the housing gasket; cavitation causes erosion-related damage inside cooling passages rather than a focused leak through the liner’s weep hole.